Which of the following statement is true about `NO_(2) and ClO_(2)`?

Options

A. Both are paramagnetic
B. Both have a bent structure
C. On cooling, both undergoes dimerisation
D. In both oxides, the central atom has an oxidation state +4.

Answer

To determine which statements are true about \( NO_2 \) and \( ClO_2 \), we will analyze the properties and structures of both molecules step by step.

### Step 1: Draw the Lewis Structures
1. **For \( NO_2 \)**:
- Nitrogen (N) has 5 valence electrons, and each oxygen (O) has 6 valence electrons.
- Total valence electrons = \( 5 + 2 \times 6 = 17 \).
- The Lewis structure shows a nitrogen atom bonded to two oxygen atoms, with one of the oxygen atoms having a double bond and the other a single bond. This results in one unpaired electron on nitrogen, making \( NO_2 \) paramagnetic.

2. **For \( ClO_2 \)**:
- Chlorine (Cl) has 7 valence electrons, and each oxygen (O) has 6 valence electrons.
- Total valence electrons = \( 7 + 2 \times 6 = 19 \).
- The Lewis structure shows a chlorine atom bonded to two oxygen atoms, with one of the oxygen atoms having a double bond and the other a single bond. This structure also results in one unpaired electron on chlorine, making \( ClO_2 \) paramagnetic as well.

### Step 2: Analyze the Statements
1. **Statement A: Both are paramagnetic.**
- True. Both \( NO_2 \) and \( ClO_2 \) have unpaired electrons, which makes them paramagnetic.

2. **Statement B: Both have a bent structure.**
- True. The presence of lone pairs on the central atoms (N in \( NO_2 \) and Cl in \( ClO_2 \)) leads to repulsion that results in a bent molecular geometry for both molecules.

3. **Statement C: On cooling, both undergo dimerization.**
- False. \( NO_2 \) can dimerize to form \( N_2O_4 \) upon cooling, but \( ClO_2 \) does not undergo dimerization due to its delocalized electrons.

4. **Statement D: In both, the central atom has an oxidation state of +4.**
- True. In \( NO_2 \), nitrogen has an oxidation state of +4, and in \( ClO_2 \), chlorine also has an oxidation state of +4.

### Conclusion
The true statements about \( NO_2 \) and \( ClO_2 \) are:
- A: Both are paramagnetic.
- B: Both have a bent structure.
- D: In both, the central atom has an oxidation state of +4.

**Final Answer**: A, B, and D are true statements.